1. Field of the Invention
The present invention relates to a method of purifying plutonium hexafluoride in the reprocessing of the spent nuclear fuel or in the recovery of fuel plutonium from the scrap using fluoride-volatility by letting the gases of fluorides flow through a layer of an adsorbent.
2. Description of the Prior Art
Heretofore several proposals and studies have been made for purifying of plutonium hexafluoride. They include the methods of the selective condensation of fission products, the thermal decomposition, and the chemical reduction of plutonium fluorides and the like. However, these method give low decontamination factors for the fluorides of the fission products without exception and they are not considered as the established methods for purifying plutonium hexafluoride. Furthermore, another method for purifying plutonium hexafluoride by adsorption-desorption using lithium fluoride as the adsorbent for plutonium hexafluoride has been proposed but with low yield of the recovered plutonium. After all, there is no effective method for purifying plutonium hexafluoride and the manufacturing process for the nuclear fuel does not include any specified purification step for plutonium hexafluoride in the present time. Thus, development of an effective method for purifying plutonium hexafluoride has been long-awaited.